Textile

ABSTRACT

A filament is made by curling a ribbon of suitable material transversely of its elongation, and drawing the curled ribbon. The resulting filament has a cross section resembling a tight spiral and may be hollow or solid. Thermoplastics may be used as the ribbon material. An apparatus and a method are disclosed for making this filament. This invention relates to filaments and methods and apparatus for making them.

United States Patent Inventor George Water-house Macclesiield, England 815,357

Apr. 11, 1969 Aug. 31 197 1 Ernest Scragg & Sons Limited Apr. 16, 1968 Great Britain Appl. No. Filed Patented Assignee Priority TEXTILE 16 Claims, 3 Drawing Figs.

57/31, 57/167, 57/157 s lnt.Cl 1002 3/06 Field 01 Search 62, 150, 151, 154, 155, 165, 167, 34, 34 HS, 157 TS, 157 S; 264/147 [56] References Cited UNITED STATES PATENTS 2,336,100 12/1943 Jacque 57/167 2,545,869 3/1951 Bailey 57/51 UX 2,900,782 8/1959 Bobkowicz 57/31 2,918,784 12/1959 Faircloth 57/167 3,017,686 1/1962 Breen et al.... 57/140 UX 3,126,699 3/1964 Lefevre et al. 57/160 3,376,698 4/1968 Whittaker 57/34 3,381,460 5/1968 Sokolowski 57/31 Primary Examiner-Stanley N. Gilreath Assistant Examiner-Werner H. Schroeder Attorney-Michael S. Striker ABSTRACT: A filament is made by curling a ribbon of suitable material transversely of its elongation, and drawing the curled ribbon. The resulting filament has a cross section resembling a tight spiral and may be hollow or solid. Thermoplastics may be used as the ribbon material. An apparatus 1 and a method are disclosed for making this filament.

This invention relates to filaments and methods and apparatus for making them.

TEXTILE The invention comprises a method for making a filament in which a curled ribbon is stretched so that it curls upon itself and its cross section becomes a tight spiral. By a curled ribbon is meant a ribbon which has been twisted or formed, in cross section, into an arc, or preferably, into a helical configuration.

The ribbon may be of drawable material such as a polyester or polyamide, such material being stretched beyond its elastic limit but short of its yield point.

At least one edge of the ribbon may be notched, slit transversely or otherwise rendered irregular as by having an edge of nonuniform thickness, or an embossed edge so that, on stretching and twisting to leave that edge on the outside of the spiral, branches are formed which protrude from the main trunk of the filament.

A composite ribbon may be. used, in which the edge may also have an extra layer or a reduced thickness of the same or dissimilar material, so that fibrillation of the edge occurs on stretching or on further twisting after stretching.

The ribbon may be heated whilst being twisted and/or stretched.

The ribbon, which may initially contain no twist, may be unwound from a bobbin using a ring and traveller of high mass, so that some drawing takes place at the unwinding stage.

The twisted and partially drawn ribbon may pass through a conical heater whilst ballooning from the ring. After leaving the conical heater, the ribbon may undergo further hot or cold drawing.

After stretching and twisting, theribbon may be fused.

The invention also comprises a filament hen made by a method as outlined above.

Such a filament may have a cross section which is a tight spiral which can be unwound into a ribbon. The edges of the ribbon on the inside and outside of the spiral may lie on helices.

A solid or hollow filament, produced from such a filament by fusing, may be of substantially cylindrical form, having at least one helically disposed rib.

A filament may also be produced having a trunk and protruding branches following a helical course around the trunk.

The invention also comprises apparatus for making a filament from a ribbon, comprising a ring and traveller for unwinding ribbon from a supply package and a heater into which the ballooning ribbon is guided from the ring. The heater may be conical.

The traveller is preferably heavy so that some drawing of the ribbon takes place in theballoon.

The apparatus may comprise a hot or cold drawing stage after the heater.

Embodiments of filaments and methods and apparatus for making them according to the invention will now be described with reference to the accompanying drawings in which FIG. l is a perspective view of a short length of one filament,

FIG. 2 is a similar view of another filament, and

FIG. 3 is a diagrammatic illustration of an apparatus.

FIG. 1 shows a filament formed by stretching and twisting a ribbon of polyester or polyamide. The ribbon was, originally, about 0.5-inch wide by 0.0l-inch thick, and was initially curled by twisting 2 or 3 turns per inch. The stretching was such that the elastic limit of the material was exceeded, but

the yield point was not reached. The more such material is permanently stretched, the finer is the resultant filament, and the more turns" there will be in the spiral.

FIG. 2 shows a filament made in similar fashion to that shown in MG. 11, but one edge which has been left on the outside of the filament during the stretching and twisting, has been transversely slit beforehand. The result is a series of branches protruding from the main trunk of the filament, and disposed helically around it. The inside and outside edges of the ribbon in fact lie on helices.

Instead of the said one edge being slit, it can be notched or otherwise rendered irregular, as by being extruded with a nonuniform thickness or by being embossed. Otherwise the ribbon can be extruded with an extra or a reduced thickness of the same or a different material at one edge, so that fibrillation occurs on stretching or on further twisting.

The main trunk of the filament constitutes a load-bearing structure, while the protruding branches can be designed to give covering power or surface quality when the filaments or a yarn made from them are woven or knitted.

Clearly, the narrower the ribbon initially, the finer will be the remitting filament. A suitable ribbon for giving a line filament would initially be 0.125-inch wide and 0.00 1 -inch thick.

FIG. 3 illustrates apparatus for making filaments from ribbon, in which ribbon 112 is unwound from a bobbin 1? by a ring and traveller. The bobbin 13 is a double flange bobbin (for ease of winding) from which, when wound, one flange is removed to facilitate unwinding.

The traveller 14 is of substantial mass (between 1.5 and 5 grams for 0.125-inch by 0.00l-inch ribbon) so that some drawing (up to a ratio of 4: 1) takes place in the balloon.

A conical heater 15 is arranged above the bobbin 13 so that the ballooning ribbon can be drawn through it by feed rollers 16. Beyond the feed rollers 16 is a further hot or cold drawing stage 17 followed by a windup.

Heater temperature for polypropylene tape is between C. and 130 C. A satisfactory draw is between 100 C. with a 5 gram traveller and at C. with a 1.5 gram traveller.

A filament so produced may be fused by heat or solvent action so that it becomes of solid or hollow substantially cylindrical form having a helically disposed external rib, and, if hollow, also an internal rib. It is possible to arrange by selection of the tape dimensions and twist that an internal rib is out of phase with an external rib.

I claim:

I. A method of making a filament, comprising the initial step of making from a predetermined material an elongated ribbon having two marginal portions one of which is to be exposed at the exterior of a filament to be made from said ribbon; the intermediate step of notching said one marginal portion of said ribbon so as to render said one marginal portion irregular; and the subsequent step of stretching said ribbon longitudinally and twisting it transversely of its elongation so as to cause said ribbon to curl upon itself in direction transversely of its elongation to thereby obtain an elongated filament whose cross section resembles a tight spiral with concomitant conversion of the irregularities of said one marginal portion into branches which protrude from the exterior of said filament.

2. A method of making a filament, comprising the initial step of making from a predetermined material an elongated ribbon having two marginal portions one: of which is to be exposed at the exterior of a filament to be made from said ribbon; the intermediate step of rendering at least said one marginal portion irregular by slitting it transversely of the elongation of said ribbon; and the subsequent step of stretching said ribbonlongitudinally and twisting it transversely of its elongation so as to cause said ribbon to curl upon itself in direction transversely of its elongation to thereby obtain an elongated filament whose cross section resembles a tight spiral with concomitant conversion of the irrgularities of said one marginal portion into branches which protrude from the exterior of said filament.

3. A method of making a filament, comprising the steps of making an elongated ribbon from a predetermined material and accommodating the ribbon on a supply bobbin; unwinding said ribbon from said supply bobbin and effecting at least some initial stretching during such unwinding; and stretching said ribbon longitudinally and twisting it transversely of its elongation so as to cause said ribbon to curl upon itself in direction transversely of its elongation to thereby obtain an elongated filament whose cross section resembles a tight spiral.

4. A method as defined in claim 3, said predetermined material being drawable and having an elastic limit and a yield point beyond its elastic limit; and wherein said subsequent step includes stretching said ribbon beyond its elastic limit but short of its yield point.

5. A method as defined in claim 3, wherein said subsequent step comprises initial twisting of said ribbon about its longitudinal axis to a helical cross-sectional configuration, and thereupon stretching in longitudinal direction.

6. A method as defined in claim 3; further comprising the step of subjecting said ribbon to elevated temperature concomitantly with said subsequent step.

7. A method as defined in claim 6; and further comprising the step of drawing said ribbon subsequent to subjecting it to said elevated temperature.

8. A method as defined in claim 7, wherein said drawing is cold drawing.

9. A method as defined in claim 3; wherein further comprising drawing is hot drawing.

10. A method as defined in claim 3; and further comprising the step of fusing said ribbon for maintaining it against reversion from its stretched and twisted condition.

11. As a novel article of manufacture, a filament composed of an elongated ribbon which is stretched and curled upon itself in direction transversely to its elongation so as to have a cross section resembling a tight spiral, said filament having a trunk and a plurality of branches projecting from said trunk exteriorly thereof and being disposed on a line which helically surrounds said trunk.

12. An article of manufacture as defined in claim 11, wherein said filament consists of polyester.

13. An article of manufacture as defined in claim 11, wherein said filament consists of polyamide.

14. An article of manufacture as defined in claim 11, wherein one longitudinal edge of the ribbon is located interiorly and the other longitudinal edge is located exteriorly of said filament, and wherein both of said edges are disposed on helices in said filament.

15. An article of manufacture as defined in claim 11, wherein said filament is hollow.

16. An article of manufacture as defined in claim 11, wherein said filament is of solid cross section. 

2. A method of making a filament, comprising the initial step of making from a predetermined material an elongated ribbon having two marginal portions one of which is to be exposed at the exterior of a filament to be made from said ribbon; the intermediate step of rendering at least said one marginal portion irregular by slitting it transversely of the elongation of said ribbon; and the subsequent step of stretching said ribbon longitudinally and twisting it transversely of its elongation so as to cause said ribbon to curl upon itself in direction transversely of its elongation to thereby obtain an elongated filament whose cross section resembles a tight spiral with concomitant conversion of the irrgularities of said one marginal portion into branches which protrude from the exterior of said filament.
 3. A method of making a filament, comprising the steps of making an elongated ribbon from a predetermined material and accommodating the ribbon on a supply bobbin; unwinding said ribbon from said supply bobbin and effecting at least some initial stretching during such unwinding; and stretching said ribbon longitudinally and twisting it transversely of its elongation so as to cause said ribbon to curl upon itself in direction transversely of its elongation to thereby obtain an elongated filament whose cross section resembles a tight spiral.
 4. A method as defined in claim 3, said predetermined material being drawable and having an elastic limit and a yield point beyond its elastic limit; and wherein said subsequent step includes stretching said ribbon beyond its elastic limit but short of its yield point.
 5. A method as defined in claim 3, wherein said subsequent step comprises initial twisting of said ribbon about its longitudinal axis to a helical cross-sectional configuration, and thereupon stretching in longitudinal direction.
 6. A method as defined in claim 3; further comprising the step of subjecting said ribbon to elevated temperature concomitantly with said subsequent step.
 7. A method as defined in claim 6; and further comprising the step of drawing said ribbon subsequent to subjecting it to said elevated temperature.
 8. A method as defined in claim 7, wherein said drawing is cold drawing.
 9. A method as defined in claim 3; wherein further comprising drawing is hot drawing.
 10. A method as defined in claim 3; and further comprising the step of fusing said ribbon for maintaining it against reversion from its stretched and twisted condition.
 11. As a novel article of manufacture, a filament composed of an elongated ribbon which is stretched and curled upon itself in direction transversely to its elongation so as to have a cross section resembling a tight spiral, said filament having a trunk and a plurality of branches projecting from said trunk exteriorly thereof and being disposed on a line which helically surrounds said trunk.
 12. An article of manufacture as defined in claim 11, wherein said filament consists of polyester.
 13. An article of manufacture as defined in claim 11, wherein said filament consists of polyamide.
 14. An article of manufacture as defined in claim 11, wherein one longitudinal edge of the ribbon is located interiorly and the other longitudinal edge is located exteriorly of said filament, and wherein both of said edges are disposed on helices in said filament.
 15. An article of manufacture as defined in claim 11, wherein said filament is hollow.
 16. An article of manufacture as defined in claim 11, wherein said filament is of solid cross section. 